Refrigerating apparatus



Oct. 27, 1936. 1.1 A.'PHILIPP I REFRIGERATING APPARATUS L Filed June 26, 1953 INVENTOR. lavas/m: P/m/PP BY 2 ATTORNEY.

Patented Oct. 27, 1936 g REFBIGEBATING APPARATUS Lawrence A. Philipp, Detroit, Mich, assignor to Kelvinator Corporation, Detroit, Mich, a corporation of Michigan Application June 26, 1933, Serial No. 677,655

9 Claims.

This invention relates to refrigerating apparatus. i

One of the objects of my invention is to provide an improved arrangement for controlling the flow of refrigerant in a refrigeratingsystem.

Another object of my invention is to providea refrigerating system of the compression type in which liquid refrigerant and some gaseous refrigerantis delivered to the low pressure side 10 thereof during initial operation of the system after a relatively long period of idleness to thereby prevent an' over-load on the motor which operates the compressor.

Another object of my invention is to arrange for controlling the amount of gaseous refrigerant delivered to the low pressure side in the aforesaid system during initial operation of the system after a long period of idleness.

Another object. is to provide for passing only m liquid refrigerant to the low pressure side of the aforesaid system during normal cyclic operation thereof.

other objects and advantages will be apparent from the following description, reference being had ,to the accompanying drawing. L

In the drawing: Fig. 1 is a diagrammatic representation of a refrigerating system embodying features of my invention; f

, Fig. 2 is an enlarged view in cross section of a refrigerant control valve shown in Fig. 1; and Fig. 3 is a modified form of a valve mechanism similar to the valve shown in Fig. 2, the view being in elevation and partly broken away.

Referring to the drawing, the numeral 20 designates, in general, a refrigerating system which includes a refrigerant condensing element 21 and a refrigerant evaporating element 23. The condensing element comprises, in general, a'motor 4o compressor unit which is preferably of the type which includes a motor and a compressor enclosed within a hermetically sealed casing 25.- The condensing element also'includes an air cooled condenser 21 and fan 28 driven by motor 29. The evaporating element 23 is disposed in a compartment 3i for cooling circulating air therein, and is also arranged for freezing substances in trays 33. The compartment 3| may be the food Zcompartment of a householdrefrigerator. It is .to be understood, however, that my invention'is not limited to household refrigerators but is suitable for use in other types of refrigerating apparatus.

The compressor of condensing element 2| with: draws gaseous refrigerant from the evaporating element 23 through a vapor conduit 35, compresses the gaseous refrigerant and delivers this high pressure refrigerant to the condenser 21 wherein it is liquefied and fromwhich it is delivered to'the evaporating element through liquid conduits 31' 5 and 38 under the control of a pressure reducing valve mechanism M in a manner about to be de- I scribed.

The valve mechanism Ml includes a valve housing 41 which provides'a valve chamber 42 in which 0 is disposed a valve proper 43 and its seat 44. Liquid refrigerant enters the chamber 42 throiigh a fitting 41 which is connected toconduit 31 and the refrigerant leaves the valve chamber 42, when the valve 43 is removed from its seat, through 15 fitting 48 which is connected with conduit 38 and which provides the seat 44 for valve 43. The valve proper is rigidly secured to an annular plate 52 which is sealed to the lowermost end of an expansible bellows 53. The uppermost end of 20 the bellows is sealed to an annular plate 58 which I is rigidly secured to the top wall of the housing 42. Thus; it will be noted that upon expansion and contraction of bellows 53 the lowermost end I thereof, together with-plate 52 and valve 43, will 25 move upwardly and downwardly as the bellows contracts and expands to open and close the valve. A bulb 6D is connected in open communication with the interior of the bellows by a conduit 62. The bellows 53, plates 52 and 58, conduit 62 and 30 bulb provide a sealed container in which I have disposed a predetermined amount of refrigerant. Preferably, the bulb 60 is placed adjacent the condenser on the side opposite the fan 28 so that the air which is circulated about the con- 35 denser will pass in contact with the bulb 60 after first passing in contact with the condenser. In

practice, it has been found that the bulb will be heated approximately 6 F. above room temperature during normal cycling of the apparatus 0- when the bulb is placed in this position. It has also been found that the bulb will be heated approximately 12 F. during initial operation of thesystem after a relatively long period of idleness. I'have also found that the,temperature of the 5 condenser is approximately 15 F. higher than" the temperature of the room in which the refrigerator is located during normal cycling, and approximately 30 F: higher during initial operation of the system after a relatively long period of 50 idleness. Thus, it will be noted that the refrigerant in the; bellows 53 will be heated less than the refrigerant which enters the valve chamber 42. Under these conditions, the refrigerant entering the chamber 42 will be at a-pressure cor- 55 example, as methyl chloride.

' responding to condensing temperature, while the refrigerant in the bellows will be at a lower pressure corresponding to approximately 6 Ff. above room temperature during normal cycling of the apparatus, or approximately 12 F. above room temperature on an initial pull down of the system.

Preferably, the system is intermittently operated. In order to control the operation of the condensing element, I have provided a thermostatically controlled switch 58 to which is connected a fluid containing bulb 51 which is secured to an outer wall of the evaporating element 23. Thus, the motor compressor unit operates in response to changes in temperatures in the evaporating element 23.

In the system hereinbefore described, I prefer to use sulphur dioxide as the refrigerant. In the event sulphur dioxide is used within the bellows and bulb 60, I provide a spring 65 to maintain the valve '43 in closed position until the pressure of the refrigerant in the valve chamber 42 is suflicient to overcome the opposing forces of the spring 65 and the pressure of the refrigerant in the bellows. By this arrangement, the valve does not remain open at all times during operation of the motor compressor unit.

During operation of the motor compressor unit, refrigerant enters the valve chamber 42 and when the pressure of the refrigerant in the chamber 42 exceeds the pressure exerted by the spring 65 and the pressure in bellows 53, the plate 52 is moved upwardly, the bellows contracted and the valve 43 removed from its seat to allow refrigerant to pass into the evaporator. When the pressure of the refrigerant in chamber 42 recedes sufliciently and the pressure of the refrigerant in bellows 53 and the pressure exerted by the spring 65 exceeds the pressure in .the chamber 42, the valve is moved in engagement with its seat to /prevent the flow of refrigerant to the evaporating element. when the system is in operation during normal cycling, I have found that some liquid refrigerant backs up into the. condenser and during periods of operation ona pull down" all of the liquid refrigerant and some gaseous refrigerant passes into the evaporating element. Thus, only liquid refrigerant is delivered to the evaporating element during nor mal cycling and some gaseous refrigerant is delivered during a pull down" to thus prevent an over-load on the motor during the initial pull down.

Fig, 3 discloses a valve 80 which in all respects corresponds to the'yalve lll with the spring 65 being omitted. This valve is arranged for connection in the system in the same manner as valve In is arranged to be connected therein. In this particular form of the invention, I introduce a quantity of refrigerant in the bellows of valve 80 and bulb 6 0, which has a pressure greaterthan the pressure of the refrigerant in other parts of the system at the same temperatures, such, for

By this arrangement, the pressure of the refrigerant in the valve bellows is great enough to avoid the use of a spring in the valve bellows.

From the foregoing, it will be apparent that I have provided an improved arrangement for controlling the flow of refrigerant in a refrigerating system. Itwill also be noted that during operation of the system on an initial pull down or when the system is started after a. period of idleness, for defrosting or the like, the refrigerant in the valve bellows is heated to a temperature which is greater than that duringnormal cycling of the system and this increased temperature results in a greater pressure being exerted on the a valve to tend to maintain it in a closed position. Thus, the amount of gaseous refrigerant which passes to the evaporating element during a pull down is limited, the amount passing through the evaporating element being only sufficient to prevent an over-load on the motor. This arrangement is also advantageous in that the temperature in the evaporating element is rapidly reduced on a pull down to a point where the switch 66 cuts out the motor compressor unit.

Although only a. preferred form of the invention has been illustrated, and that form described in detail, it will be apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What I claim as my invention is:

l. A refrigerating system comprising, in combination, a high pressure side, a low pressure side, means responsive to the pressure of the refrigerant in the high pressure side for controlling the admission of refrigerant to said low pressure side, and means responsive to changes in temperature of the ambient air. which cooled the high pressure side for controlling the operation bination, an evaporator, means for circulating,

refrigerant through the evaporator including a condenser, means responsive to the pressure of the refrigerant in said condenser for controlling the flow of refrigerant to the evaporator, and means arranged in heat receiving relation to but Spaced from said condenser for controlling the operation of said second named means.

3. Refrigerating apparatus comprising, in combination, an evaporator, means for circulating refrigerant through the evaporator including heat dissipating means arranged to increase in temperature when refrigerant is circulated, said heat dissipating means being cooled by a medium flowing thereover, means responsive to the pressure of the refrigerant in said circulating means for controlling the flow of refrigerant to the evaporator, and means arranged in heat receiving relation to but spaced from said heat dissipating means and subjected to the temperature of the cooling medium for varying the operation of said controlling means;

4. Refrigerating apparatus comprising, in combination, an evaporator, means for circulating refrigerant through said evaporator including a condenser, means responsive to the pressure of 'the refrigerant in said condenser for controlling the flow of refrigerant to the evaporator, means for circulating air about the condenser, and means spaced from the condenser and arranged in the path of said air after it has passed about the condenser for controlling the operation of said second named means.

5. Refrigerating apparatus comprising, in combination, an evaporator, means for circulating refrigerant through said evaporator including a condenser, means responsive to the pressure of the refrigerant in said condenser for controlling the flow of refrigerant to the evaporator, and means containing a refrigerant whose pressure is higher than the refrigerant in-said condenser at the same temperatures and being arranged in heat receiving relation to said condenser for controlling the operation of said second named means.

aouaeos .6. A refrigerating system comprising a high pressure side, a low pressure side, an expansion valve operable to pass liquid refrigerant only from the high pressure side to the low pressure side during one period of operation and to pass both densing element, an evaporating element, expan sion valve means operable to pass only liquid refrigerant from the condensing element 'tothe evaporating element during normal cycling operation of the condensing element, and to pass liquid and gaseous refrigerant to the evaporating element during abnormal operation of said condensing element and temperature responsive means for actuating said valve.

8. The method of refrigeration in a system having high and low pressure portions which consists in supplying refrigerant from the high to the low pressure portion under the influence of the pressure exerted in the high pressure portion and modifying the passage of refrigerant to the low pressure portion in response to changes in temperatures prevailing in the cooling medium adjacent the high pressure portion.

9. The method of refrigeration in a system having high and low pressure portions which consists in supplying refrigerant from the high to the low pressure portion under the influence of the pressure exerted in the high pressure portion, circulating a cooling medium for cooling the high pressure portion, and modifying the passage of refrigerant to the low pressure portion in response to temperature changes of the cooling medium which is at variance with respect to the pressure temperatures in the highpressure portion.

IIAWRENCE. A. PHILIPP. 

